CHARACTERIZATION MICROBIOLOGICAL, BY CONVENTIONAL METHOD, OF “DOCE DE LEITE”, CONDENSED MILK AND MINAS PADRÃO CHEESE SOLD IN SUPERMARKETS IN JUIZ DE FORA (MG) AND STANDARDIZATION OF MULTIPLEX REACTION FOR DETECTION OF PATHOGENS USING REAL-TIME PCR TECHNIQ

Abstract

Dairy products are food with exceptional nutritional value and are widely consumed by the population. However, they are also excellent culture medium for many microorganisms, and is therefore liable to microbiological contamination by different agents which may lead to diseases manifested by the action of pathogens or their toxins. The attainment of safe food depends among other factors, of the analysis methods used, which should provide fast and reliable results that allow the monitoring of microbiological safety of food, either by industry or by the supervisory bodies and for this, alternative methods have been developed for the detection and quantification of pathogens. The first objective of this study was to characterize microbiologically, by conventional method, samples of "doce de leite", condensed milk and Minas Padrão cheese with SIF, produced in several states in Brazil and sold in supermarkets in Juiz de Fora (MG). Standard count analysis were made in standard plate for mesophyll, yeasts and molds, coliforms at 30º C and 45º C, Staphylococcus spp. coagulase positive and negative, as well as Salmonella sp. and Listeria monocytogenes. High standard counts on plates of mesophyll, yeasts and Staphylococcus spp. coagulase-negative were found in three products. The second objective was to propose an alternative approach to classical, to produce faster results and high specificity for detection of main pathogen contaminants of dairy products and transmitting of food diseases, using real-time PCR technique. A multiplex reaction was standardized for detection of Salmonella enteric var thyphimurium and Staphylococcus aureus. This work will contribute to the rare literature on microbial contaminants from "doce de leite", condensed milk and standard, providing scientific data to the academy, regulatory authorities and industry, envisioning the possibility of using alternative microbiological diagnosis methods instead of classic for classical that provide faster and more sensitive results.